The expression "end machining" is to be understood to mean the complete machining of the end of a shaft, of a journal, or of a tube with a single turning tool, which has a plurality of firmly adjusted cutting plate supports with cutting plates arranged thereon. Thus, for example, a surface machining of the end face, a machining of the outside diameter over a limited length, the working of bevels on the outside diameter and the production of a centring bore is performed in a single axial feed of the turning tool relative to the workpiece or vice versa.
In a known turning tool of the type initially defined, the toolholders are screwed firmly to the end face of the base element. In order to achieve accurate positioning of the toolholder, the end face in this case has grooves in which the toolholders engage. At least one cutting plate support is radially adjustable by means of an adjusting screw on each toolholder. Although it is possible with this turning tool to machine different diameters within a certain range of diameters, nevertheless the machine surfaces always have the same distance from the flat end surface of the machined end of the workpiece. It is only by exchanging the toolholders for other toolholders adapted to the workpiece to be machined that the turning tool can be used for another workpiece. However, since workpiece ends may have the widest variety of shapes, it would be necessary to have a large number of different toolholders in stock, or to prepare suitable toolholders each time. Even the production of the grooves in the end face of the base element is an onerous operation. In addition to this, the surfaces engaging the groove must be accurately machined on each toolholder.
It is the underlying aim of the invention to develop a turning tool for machining the ends of shafts, journals, tubes and the like of the type initially defined, which permits the machining of a large number of different workpiece ends with a few basic types of toolholder, which can be adapted to the relevant workpiece end without substantial modification, and is at the same time of simple construction.
This is achieved according to the invention in that the base element has for each toolholder at least one housing bore parallel to the axis of rotation, and the toolholder has a cylindrical shank fitting into the latter, that each toolholder has an adjusting screw which is screwable parallel to the axis of rotation or the shank axis, and is braced against the base element or against a support element connected to the latter, and that means for clamping and for securing against rotation are provided between the shank and the base element, by means of which the shank is clampable in the adjusted axial position.
The production of the entire turning tool is greatly simplified by the adoption of cylindrical housing bores and cylindrical shank fitting into the latter. The disc-shaped base element with the cylindrical housing bores can then be produced so simply that even the user of the tool can prepare such a base element for himself if the workpiece to be machined should make this necessary. However, this is not likely to be the case generally, because due to the adjustability of the toolholders in the axial direction and the additional adjustability of the cutting plate supports in the radial direction, the turning tool can be adapted to the widest variety of workpiece ends to be machined. It is also possible to effect an adaptation by exchanging cutting plate supports for such of a different shape.
The possibilities of adaptation can be extended still further if the base element has a plurality of housing bores arranged at different radial distances from the axis of rotation. In fact, if the radial adjustment range of a cutting plate support is not sufficient, then the relevant toolholder can easily be removed from the base element by releasing the clamping device and its shank can be inserted into a housing bore located radially farther outwards or farther inwards and clamped there. The turning tool therefore permits machining operations over an extremely wide range of diameters.
It is found that, in a preferred embodiment of the invention, only two basic forms of toolholders are required and a large number of the widest variety of workpiece ends can be machined with them.